In computer science, a data structure is a data organization, management, and storage format that enables efficient access and modification. More precisely, a data structure is a collection of data values, the relationships among them, and the functions or operations that can be applied to the data.
An array is a data structure that stores a collection of data values in contiguous memory locations.
let array = [4,3,8,1,0,14,6];
| Memory Location | Value |
|---|---|
| 1000 | 4 |
| 1001 | 3 |
| 1002 | 8 |
| 1003 | 1 |
| 1004 | 0 |
| 1005 | 14 |
| 1006 | 6 |
Accessing an element in an array is done by indexing into it.
array[0] // 4 (index 0 is the first element) (1000)
array[1] // 3 (index 1 is the second element) (1001)
array[2] // 8 (index 2 is the third element) (1002)
array[3] // 1 (index 3 is the fourth element) (1003)
array[4] // 0 (index 4 is the fifth element) (1004)
array[5] // 14 (index 5 is the sixth element) (1005)
array[6] // 6 (index 6 is the seventh element) (1006)
A linked list is a data structure that consists of a group of nodes where each node contains a data value and a reference (or link) to the next node in the list.
let list = [4,3,1,0,14,6];
| Memory Location | Value |
|---|---|
| 1000 | 4 |
| 1001 | 1008 |
| 1002 | 1 |
| 1003 | 1004 |
| 1004 | 0 |
| 1005 | 1006 |
| 1006 | 14 |
| 1007 | 1010 |
| 1008 | 3 |
| 1009 | 1002 |
| 1010 | 6 |
| 1011 | 1000 |
Accessing an element in a linked list is done by traversing the list and finding the element at the correct index.
index 0 value is 4 with memory location 1000 and pointer to next node 1008
index 1 value is 3 with memory location 1008 and pointer to next node 1002
index 2 value is 1 with memory location 1002 and pointer to next node 1004
index 3 value is 0 with memory location 1004 and pointer to next node 1006
index 4 value is 14 with memory location 1006 and pointer to next node 1010
index 5 value is 6 with memory location 1010 and pointer to first node 1000
A stack is a data structure that stores a collection of data values in a LIFO (last in, first out) order.